The present invention relates to a magnetic recording-and-reproducing apparatus provided with a magnetic head to record information on and to reproduce information from a magnetic disk and, more specifically, a lifting mechanism included in a magnetic recording-and-reproducing apparatus to move a magnetic head relative to a magnetic disk.
A magnetic recording-and-reproducing apparatus designed to record information on and reproducing information from a magnetic disk contained in a disk cartridge is provided with a head moving mechanism which is driven for reciprocating movement by a motor. When recording information on or reproducing information from a magnetic disk, the head moving mechanism holding a pair of magnetic heads respectively on the opposite sides of a magnetic disk moves in directions along the radius of the magnetic disk.
A known head lifting mechanism employed in such a conventional magnetic recording-and-reproducing apparatus has a slide plate supported for forward and backward movements on a chassis, and a cartridge holder supported for vertical movement on the chassis, and the cartridge holder is moved vertically to move an upper magnetic head vertically. In this magnetic head lifting mechanism, the cartridge holder is held at an upper unloading position by the slide plate, and the upper magnetic head is at an upper position and in contact with the upper surface of the cartridge holder of the head moving mechanism when the cartridge holder is not loaded with any disk cartridge. When a disk cartridge is loaded into the cartridge holder, a disk cartridge loading action moves the slide plate forward, and the cartridge holder moves down along a cam groove formed in the slide plate to a loading position. Consequently, the disk cartridge held on the cartridge holder, and the upper magnetic head in contact with the upper surface of the cartridge holder move down, so that the magnetic disk is positioned between the upper and the lower magnetic head. In this state, the magnetic disk is rotated and the head moving mechanism is reciprocated along the radius of the magnetic disk to record information on or to reproduce information from the magnetic disk.
In operating the conventional magnetic recording-and-reproducing apparatus, the cartridge holder needs to be lowered together with the disk cartridge toward the lower magnetic head after inserting the disk cartridge through a slot formed in the front wall of the magnetic recording-and-reproducing apparatus into the cartridge holder. Therefore, the disk cartridge must completely be inserted through the slot into the cartridge holder in order to move the disk cartridge vertically. Such an arrangement is an obstacle to the reduction of the depth of the magnetic recording-and-reproducing apparatus. Since the upper magnetic head collides violently through the magnetic disk against the lower magnetic head when the disk cartridge is lowered, the magnetic heads are liable to be damaged.
The applicant of the present patent application made efforts to make a magnetic recording-and-reproducing apparatus fit for practical use. This magnetic recording-and-reproducing apparatus has a cartridge holder fixed to a chassis, an auxiliary chassis supported for forward, backward and vertical movements, and a head moving mechanism mounted on the auxiliary chassis so as to be moved vertically relative to a disk cartridge. Although this magnetic recording-and-reproducing apparatus solves the foregoing problems in the conventional magnetic recording-and-reproducing apparatus, the upper magnetic head included in the head moving mechanism cannot vertically be moved by the cartridge holder, because the cartridge holder holding the disk cartridge is fixed to the chassis, and needs another lifting mechanism for vertically moving the magnetic head. It is a problem to form such a lifting mechanism in a simple construction.